This invention is directed to an abrasive article having an abrasive coating containing a siloxane polymer.
U.S. Pat. No. 5,152,917 (Pieper et al.) reports abrasive articles which have a structured abrasive coating comprising a plurality of precisely shaped abrasive composites bonded to a backing. The precisely shaped abrasive composites can have a variety of geometric shapes and are formed of a plurality of abrasive particles dispersed in a cured binder.
Structured abrasives can be made in a variety of different coating processes such as reported in U.S. Pat. No. 5,304,223 (Pieper et al.), U.S. Pat. No. 5,435,816 (Spurgeon et al.), U.S. Pat. No. 5,672,097 (Hoopman et al.), and WO 97/12727 (Hoopman et al.). One method of making structured abrasive is to first coat an abrasive slurry (i.e., a plurality of abrasive particles dispersed in a binder precursor) onto a backing. The slurry-coated backing is then brought into contact with a production tool comprising a series of precisely shaped cavities. The cavities have essentially the inverse shape and dimensions of the desired abrasive composites. The abrasive slurry flows into the cavities of the production tool. Next, the binder precursor is exposed to conditions to cure the binder precursor to form an abrasive coating which is bonded to the backing.
The production tool may comprise a continuous thermoplastic sheet or belt that has the desired pattern of precisely shaped cavities embossed into the surface. For a variety of reasons, it is desirable to re-use the production tool multiple times before disposal. In order to re-use the production tool, the previously manufactured abrasive composites must cleanly separate from the cavities of the production tool. If residual portions of abrasive composites remain in the production tool, the cavities will be obstructed, thereby preventing subsequently coated slurry from completely filling the cavities. This may result in a malformed abrasive coating which does not have the desired precisely shaped surface and/or abrasive coating weight.
What is desired is a means to re-use a production tool many times, without adversely affecting the abrasive article formed therefrom.